2 * Copyright (c) International Business Machines Corp., 2006
3 * Copyright (c) Nokia Corporation, 2007
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 * Author: Artem Bityutskiy (Битюцкий Артём),
24 * This file includes UBI initialization and building of UBI devices.
26 * When UBI is initialized, it attaches all the MTD devices specified as the
27 * module load parameters or the kernel boot parameters. If MTD devices were
28 * specified, UBI does not attach any MTD device, but it is possible to do
29 * later using the "UBI control device".
31 * At the moment we only attach UBI devices by scanning, which will become a
32 * bottleneck when flashes reach certain large size. Then one may improve UBI
33 * and add other methods, although it does not seem to be easy to do.
36 #include <linux/err.h>
37 #include <linux/module.h>
38 #include <linux/moduleparam.h>
39 #include <linux/stringify.h>
40 #include <linux/stat.h>
41 #include <linux/miscdevice.h>
42 #include <linux/log2.h>
43 #include <linux/kthread.h>
44 #include <linux/reboot.h>
47 /* Maximum length of the 'mtd=' parameter */
48 #define MTD_PARAM_LEN_MAX 64
51 * struct mtd_dev_param - MTD device parameter description data structure.
52 * @name: MTD device name or number string
53 * @vid_hdr_offs: VID header offset
55 struct mtd_dev_param {
56 char name[MTD_PARAM_LEN_MAX];
60 /* Numbers of elements set in the @mtd_dev_param array */
63 /* MTD devices specification parameters */
64 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
66 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
67 struct class *ubi_class;
69 /* Slab cache for wear-leveling entries */
70 struct kmem_cache *ubi_wl_entry_slab;
72 /* UBI control character device */
73 static struct miscdevice ubi_ctrl_cdev = {
74 .minor = MISC_DYNAMIC_MINOR,
76 .fops = &ubi_ctrl_cdev_operations,
79 /* All UBI devices in system */
80 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
82 /* Serializes UBI devices creations and removals */
83 DEFINE_MUTEX(ubi_devices_mutex);
85 /* Protects @ubi_devices and @ubi->ref_count */
86 static DEFINE_SPINLOCK(ubi_devices_lock);
88 /* "Show" method for files in '/<sysfs>/class/ubi/' */
89 static ssize_t ubi_version_show(struct class *class, char *buf)
91 return sprintf(buf, "%d\n", UBI_VERSION);
94 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
95 static struct class_attribute ubi_version =
96 __ATTR(version, S_IRUGO, ubi_version_show, NULL);
98 static ssize_t dev_attribute_show(struct device *dev,
99 struct device_attribute *attr, char *buf);
101 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
102 static struct device_attribute dev_eraseblock_size =
103 __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
104 static struct device_attribute dev_avail_eraseblocks =
105 __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
106 static struct device_attribute dev_total_eraseblocks =
107 __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
108 static struct device_attribute dev_volumes_count =
109 __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
110 static struct device_attribute dev_max_ec =
111 __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
112 static struct device_attribute dev_reserved_for_bad =
113 __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
114 static struct device_attribute dev_bad_peb_count =
115 __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
116 static struct device_attribute dev_max_vol_count =
117 __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
118 static struct device_attribute dev_min_io_size =
119 __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
120 static struct device_attribute dev_bgt_enabled =
121 __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
122 static struct device_attribute dev_mtd_num =
123 __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
126 * ubi_volume_notify - send a volume change notification.
127 * @ubi: UBI device description object
128 * @vol: volume description object of the changed volume
129 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
131 * This is a helper function which notifies all subscribers about a volume
132 * change event (creation, removal, re-sizing, re-naming, updating). Returns
133 * zero in case of success and a negative error code in case of failure.
135 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
137 struct ubi_notification nt;
139 ubi_do_get_device_info(ubi, &nt.di);
140 ubi_do_get_volume_info(ubi, vol, &nt.vi);
141 return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
145 * ubi_notify_all - send a notification to all volumes.
146 * @ubi: UBI device description object
147 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
148 * @nb: the notifier to call
150 * This function walks all volumes of UBI device @ubi and sends the @ntype
151 * notification for each volume. If @nb is %NULL, then all registered notifiers
152 * are called, otherwise only the @nb notifier is called. Returns the number of
153 * sent notifications.
155 int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
157 struct ubi_notification nt;
160 ubi_do_get_device_info(ubi, &nt.di);
162 mutex_lock(&ubi->device_mutex);
163 for (i = 0; i < ubi->vtbl_slots; i++) {
165 * Since the @ubi->device is locked, and we are not going to
166 * change @ubi->volumes, we do not have to lock
167 * @ubi->volumes_lock.
169 if (!ubi->volumes[i])
172 ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
174 nb->notifier_call(nb, ntype, &nt);
176 blocking_notifier_call_chain(&ubi_notifiers, ntype,
180 mutex_unlock(&ubi->device_mutex);
186 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
187 * @nb: the notifier to call
189 * This function walks all UBI devices and volumes and sends the
190 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
191 * registered notifiers are called, otherwise only the @nb notifier is called.
192 * Returns the number of sent notifications.
194 int ubi_enumerate_volumes(struct notifier_block *nb)
199 * Since the @ubi_devices_mutex is locked, and we are not going to
200 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
202 for (i = 0; i < UBI_MAX_DEVICES; i++) {
203 struct ubi_device *ubi = ubi_devices[i];
207 count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
214 * ubi_get_device - get UBI device.
215 * @ubi_num: UBI device number
217 * This function returns UBI device description object for UBI device number
218 * @ubi_num, or %NULL if the device does not exist. This function increases the
219 * device reference count to prevent removal of the device. In other words, the
220 * device cannot be removed if its reference count is not zero.
222 struct ubi_device *ubi_get_device(int ubi_num)
224 struct ubi_device *ubi;
226 spin_lock(&ubi_devices_lock);
227 ubi = ubi_devices[ubi_num];
229 ubi_assert(ubi->ref_count >= 0);
231 get_device(&ubi->dev);
233 spin_unlock(&ubi_devices_lock);
239 * ubi_put_device - drop an UBI device reference.
240 * @ubi: UBI device description object
242 void ubi_put_device(struct ubi_device *ubi)
244 spin_lock(&ubi_devices_lock);
246 put_device(&ubi->dev);
247 spin_unlock(&ubi_devices_lock);
251 * ubi_get_by_major - get UBI device by character device major number.
252 * @major: major number
254 * This function is similar to 'ubi_get_device()', but it searches the device
255 * by its major number.
257 struct ubi_device *ubi_get_by_major(int major)
260 struct ubi_device *ubi;
262 spin_lock(&ubi_devices_lock);
263 for (i = 0; i < UBI_MAX_DEVICES; i++) {
264 ubi = ubi_devices[i];
265 if (ubi && MAJOR(ubi->cdev.dev) == major) {
266 ubi_assert(ubi->ref_count >= 0);
268 get_device(&ubi->dev);
269 spin_unlock(&ubi_devices_lock);
273 spin_unlock(&ubi_devices_lock);
279 * ubi_major2num - get UBI device number by character device major number.
280 * @major: major number
282 * This function searches UBI device number object by its major number. If UBI
283 * device was not found, this function returns -ENODEV, otherwise the UBI device
284 * number is returned.
286 int ubi_major2num(int major)
288 int i, ubi_num = -ENODEV;
290 spin_lock(&ubi_devices_lock);
291 for (i = 0; i < UBI_MAX_DEVICES; i++) {
292 struct ubi_device *ubi = ubi_devices[i];
294 if (ubi && MAJOR(ubi->cdev.dev) == major) {
295 ubi_num = ubi->ubi_num;
299 spin_unlock(&ubi_devices_lock);
304 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
305 static ssize_t dev_attribute_show(struct device *dev,
306 struct device_attribute *attr, char *buf)
309 struct ubi_device *ubi;
312 * The below code looks weird, but it actually makes sense. We get the
313 * UBI device reference from the contained 'struct ubi_device'. But it
314 * is unclear if the device was removed or not yet. Indeed, if the
315 * device was removed before we increased its reference count,
316 * 'ubi_get_device()' will return -ENODEV and we fail.
318 * Remember, 'struct ubi_device' is freed in the release function, so
319 * we still can use 'ubi->ubi_num'.
321 ubi = container_of(dev, struct ubi_device, dev);
322 ubi = ubi_get_device(ubi->ubi_num);
326 if (attr == &dev_eraseblock_size)
327 ret = sprintf(buf, "%d\n", ubi->leb_size);
328 else if (attr == &dev_avail_eraseblocks)
329 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
330 else if (attr == &dev_total_eraseblocks)
331 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
332 else if (attr == &dev_volumes_count)
333 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
334 else if (attr == &dev_max_ec)
335 ret = sprintf(buf, "%d\n", ubi->max_ec);
336 else if (attr == &dev_reserved_for_bad)
337 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
338 else if (attr == &dev_bad_peb_count)
339 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
340 else if (attr == &dev_max_vol_count)
341 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
342 else if (attr == &dev_min_io_size)
343 ret = sprintf(buf, "%d\n", ubi->min_io_size);
344 else if (attr == &dev_bgt_enabled)
345 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
346 else if (attr == &dev_mtd_num)
347 ret = sprintf(buf, "%d\n", ubi->mtd->index);
355 static void dev_release(struct device *dev)
357 struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
363 * ubi_sysfs_init - initialize sysfs for an UBI device.
364 * @ubi: UBI device description object
366 * This function returns zero in case of success and a negative error code in
369 static int ubi_sysfs_init(struct ubi_device *ubi)
373 ubi->dev.release = dev_release;
374 ubi->dev.devt = ubi->cdev.dev;
375 ubi->dev.class = ubi_class;
376 dev_set_name(&ubi->dev, UBI_NAME_STR"%d", ubi->ubi_num);
377 err = device_register(&ubi->dev);
381 err = device_create_file(&ubi->dev, &dev_eraseblock_size);
384 err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
387 err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
390 err = device_create_file(&ubi->dev, &dev_volumes_count);
393 err = device_create_file(&ubi->dev, &dev_max_ec);
396 err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
399 err = device_create_file(&ubi->dev, &dev_bad_peb_count);
402 err = device_create_file(&ubi->dev, &dev_max_vol_count);
405 err = device_create_file(&ubi->dev, &dev_min_io_size);
408 err = device_create_file(&ubi->dev, &dev_bgt_enabled);
411 err = device_create_file(&ubi->dev, &dev_mtd_num);
416 * ubi_sysfs_close - close sysfs for an UBI device.
417 * @ubi: UBI device description object
419 static void ubi_sysfs_close(struct ubi_device *ubi)
421 device_remove_file(&ubi->dev, &dev_mtd_num);
422 device_remove_file(&ubi->dev, &dev_bgt_enabled);
423 device_remove_file(&ubi->dev, &dev_min_io_size);
424 device_remove_file(&ubi->dev, &dev_max_vol_count);
425 device_remove_file(&ubi->dev, &dev_bad_peb_count);
426 device_remove_file(&ubi->dev, &dev_reserved_for_bad);
427 device_remove_file(&ubi->dev, &dev_max_ec);
428 device_remove_file(&ubi->dev, &dev_volumes_count);
429 device_remove_file(&ubi->dev, &dev_total_eraseblocks);
430 device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
431 device_remove_file(&ubi->dev, &dev_eraseblock_size);
432 device_unregister(&ubi->dev);
436 * kill_volumes - destroy all volumes.
437 * @ubi: UBI device description object
439 static void kill_volumes(struct ubi_device *ubi)
443 for (i = 0; i < ubi->vtbl_slots; i++)
445 ubi_free_volume(ubi, ubi->volumes[i]);
449 * free_user_volumes - free all user volumes.
450 * @ubi: UBI device description object
452 * Normally the volumes are freed at the release function of the volume device
453 * objects. However, on error paths the volumes have to be freed before the
454 * device objects have been initialized.
456 static void free_user_volumes(struct ubi_device *ubi)
460 for (i = 0; i < ubi->vtbl_slots; i++)
461 if (ubi->volumes[i]) {
462 kfree(ubi->volumes[i]->eba_tbl);
463 kfree(ubi->volumes[i]);
468 * uif_init - initialize user interfaces for an UBI device.
469 * @ubi: UBI device description object
471 * This function returns zero in case of success and a negative error code in
472 * case of failure. Note, this function destroys all volumes if it fails.
474 static int uif_init(struct ubi_device *ubi)
479 sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
482 * Major numbers for the UBI character devices are allocated
483 * dynamically. Major numbers of volume character devices are
484 * equivalent to ones of the corresponding UBI character device. Minor
485 * numbers of UBI character devices are 0, while minor numbers of
486 * volume character devices start from 1. Thus, we allocate one major
487 * number and ubi->vtbl_slots + 1 minor numbers.
489 err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
491 ubi_err("cannot register UBI character devices");
495 ubi_assert(MINOR(dev) == 0);
496 cdev_init(&ubi->cdev, &ubi_cdev_operations);
497 dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
498 ubi->cdev.owner = THIS_MODULE;
500 err = cdev_add(&ubi->cdev, dev, 1);
502 ubi_err("cannot add character device");
506 err = ubi_sysfs_init(ubi);
510 for (i = 0; i < ubi->vtbl_slots; i++)
511 if (ubi->volumes[i]) {
512 err = ubi_add_volume(ubi, ubi->volumes[i]);
514 ubi_err("cannot add volume %d", i);
524 ubi_sysfs_close(ubi);
525 cdev_del(&ubi->cdev);
527 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
528 ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
533 * uif_close - close user interfaces for an UBI device.
534 * @ubi: UBI device description object
536 * Note, since this function un-registers UBI volume device objects (@vol->dev),
537 * the memory allocated voe the volumes is freed as well (in the release
540 static void uif_close(struct ubi_device *ubi)
543 ubi_sysfs_close(ubi);
544 cdev_del(&ubi->cdev);
545 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
549 * free_internal_volumes - free internal volumes.
550 * @ubi: UBI device description object
552 static void free_internal_volumes(struct ubi_device *ubi)
556 for (i = ubi->vtbl_slots;
557 i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
558 kfree(ubi->volumes[i]->eba_tbl);
559 kfree(ubi->volumes[i]);
564 * attach_by_scanning - attach an MTD device using scanning method.
565 * @ubi: UBI device descriptor
567 * This function returns zero in case of success and a negative error code in
570 * Note, currently this is the only method to attach UBI devices. Hopefully in
571 * the future we'll have more scalable attaching methods and avoid full media
572 * scanning. But even in this case scanning will be needed as a fall-back
573 * attaching method if there are some on-flash table corruptions.
575 static int attach_by_scanning(struct ubi_device *ubi)
578 struct ubi_scan_info *si;
584 ubi->bad_peb_count = si->bad_peb_count;
585 ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
586 ubi->max_ec = si->max_ec;
587 ubi->mean_ec = si->mean_ec;
589 err = ubi_read_volume_table(ubi, si);
593 err = ubi_wl_init_scan(ubi, si);
597 err = ubi_eba_init_scan(ubi, si);
601 ubi_scan_destroy_si(si);
607 free_internal_volumes(ubi);
610 ubi_scan_destroy_si(si);
615 * io_init - initialize I/O sub-system for a given UBI device.
616 * @ubi: UBI device description object
618 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
620 * o EC header is always at offset zero - this cannot be changed;
621 * o VID header starts just after the EC header at the closest address
622 * aligned to @io->hdrs_min_io_size;
623 * o data starts just after the VID header at the closest address aligned to
626 * This function returns zero in case of success and a negative error code in
629 static int io_init(struct ubi_device *ubi)
631 if (ubi->mtd->numeraseregions != 0) {
633 * Some flashes have several erase regions. Different regions
634 * may have different eraseblock size and other
635 * characteristics. It looks like mostly multi-region flashes
636 * have one "main" region and one or more small regions to
637 * store boot loader code or boot parameters or whatever. I
638 * guess we should just pick the largest region. But this is
641 ubi_err("multiple regions, not implemented");
645 if (ubi->vid_hdr_offset < 0)
649 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
650 * physical eraseblocks maximum.
653 ubi->peb_size = ubi->mtd->erasesize;
654 ubi->peb_count = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
655 ubi->flash_size = ubi->mtd->size;
657 if (ubi->mtd->block_isbad && ubi->mtd->block_markbad)
658 ubi->bad_allowed = 1;
660 ubi->min_io_size = ubi->mtd->writesize;
661 ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
664 * Make sure minimal I/O unit is power of 2. Note, there is no
665 * fundamental reason for this assumption. It is just an optimization
666 * which allows us to avoid costly division operations.
668 if (!is_power_of_2(ubi->min_io_size)) {
669 ubi_err("min. I/O unit (%d) is not power of 2",
674 ubi_assert(ubi->hdrs_min_io_size > 0);
675 ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
676 ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
678 /* Calculate default aligned sizes of EC and VID headers */
679 ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
680 ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
682 dbg_msg("min_io_size %d", ubi->min_io_size);
683 dbg_msg("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
684 dbg_msg("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
685 dbg_msg("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
687 if (ubi->vid_hdr_offset == 0)
689 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
692 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
693 ~(ubi->hdrs_min_io_size - 1);
694 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
695 ubi->vid_hdr_aloffset;
698 /* Similar for the data offset */
699 ubi->leb_start = ubi->vid_hdr_offset + UBI_EC_HDR_SIZE;
700 ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
702 dbg_msg("vid_hdr_offset %d", ubi->vid_hdr_offset);
703 dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
704 dbg_msg("vid_hdr_shift %d", ubi->vid_hdr_shift);
705 dbg_msg("leb_start %d", ubi->leb_start);
707 /* The shift must be aligned to 32-bit boundary */
708 if (ubi->vid_hdr_shift % 4) {
709 ubi_err("unaligned VID header shift %d",
715 if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
716 ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
717 ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
718 ubi->leb_start & (ubi->min_io_size - 1)) {
719 ubi_err("bad VID header (%d) or data offsets (%d)",
720 ubi->vid_hdr_offset, ubi->leb_start);
725 * Set maximum amount of physical erroneous eraseblocks to be 10%.
726 * Erroneous PEB are those which have read errors.
728 ubi->max_erroneous = ubi->peb_count / 10;
729 if (ubi->max_erroneous < 16)
730 ubi->max_erroneous = 16;
731 dbg_msg("max_erroneous %d", ubi->max_erroneous);
734 * It may happen that EC and VID headers are situated in one minimal
735 * I/O unit. In this case we can only accept this UBI image in
738 if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
739 ubi_warn("EC and VID headers are in the same minimal I/O unit, "
740 "switch to read-only mode");
744 ubi->leb_size = ubi->peb_size - ubi->leb_start;
746 if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
747 ubi_msg("MTD device %d is write-protected, attach in "
748 "read-only mode", ubi->mtd->index);
752 ubi_msg("physical eraseblock size: %d bytes (%d KiB)",
753 ubi->peb_size, ubi->peb_size >> 10);
754 ubi_msg("logical eraseblock size: %d bytes", ubi->leb_size);
755 ubi_msg("smallest flash I/O unit: %d", ubi->min_io_size);
756 if (ubi->hdrs_min_io_size != ubi->min_io_size)
757 ubi_msg("sub-page size: %d",
758 ubi->hdrs_min_io_size);
759 ubi_msg("VID header offset: %d (aligned %d)",
760 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
761 ubi_msg("data offset: %d", ubi->leb_start);
764 * Note, ideally, we have to initialize ubi->bad_peb_count here. But
765 * unfortunately, MTD does not provide this information. We should loop
766 * over all physical eraseblocks and invoke mtd->block_is_bad() for
767 * each physical eraseblock. So, we skip ubi->bad_peb_count
768 * uninitialized and initialize it after scanning.
775 * autoresize - re-size the volume which has the "auto-resize" flag set.
776 * @ubi: UBI device description object
777 * @vol_id: ID of the volume to re-size
779 * This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
780 * the volume table to the largest possible size. See comments in ubi-header.h
781 * for more description of the flag. Returns zero in case of success and a
782 * negative error code in case of failure.
784 static int autoresize(struct ubi_device *ubi, int vol_id)
786 struct ubi_volume_desc desc;
787 struct ubi_volume *vol = ubi->volumes[vol_id];
788 int err, old_reserved_pebs = vol->reserved_pebs;
791 * Clear the auto-resize flag in the volume in-memory copy of the
792 * volume table, and 'ubi_resize_volume()' will propagate this change
795 ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
797 if (ubi->avail_pebs == 0) {
798 struct ubi_vtbl_record vtbl_rec;
801 * No available PEBs to re-size the volume, clear the flag on
804 memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
805 sizeof(struct ubi_vtbl_record));
806 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
808 ubi_err("cannot clean auto-resize flag for volume %d",
812 err = ubi_resize_volume(&desc,
813 old_reserved_pebs + ubi->avail_pebs);
815 ubi_err("cannot auto-resize volume %d", vol_id);
821 ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id,
822 vol->name, old_reserved_pebs, vol->reserved_pebs);
827 * ubi_reboot_notifier - halt UBI transactions immediately prior to a reboot.
828 * @n: reboot notifier object
829 * @state: SYS_RESTART, SYS_HALT, or SYS_POWER_OFF
830 * @cmd: pointer to command string for RESTART2
832 * This function stops the UBI background thread so that the flash device
833 * remains quiescent when Linux restarts the system. Any queued work will be
834 * discarded, but this function will block until do_work() finishes if an
835 * operation is already in progress.
837 * This function solves a real-life problem observed on NOR flashes when an
838 * PEB erase operation starts, then the system is rebooted before the erase is
839 * finishes, and the boot loader gets confused and dies. So we prefer to finish
840 * the ongoing operation before rebooting.
842 static int ubi_reboot_notifier(struct notifier_block *n, unsigned long state,
845 struct ubi_device *ubi;
847 ubi = container_of(n, struct ubi_device, reboot_notifier);
849 kthread_stop(ubi->bgt_thread);
850 ubi_sync(ubi->ubi_num);
855 * ubi_attach_mtd_dev - attach an MTD device.
856 * @mtd: MTD device description object
857 * @ubi_num: number to assign to the new UBI device
858 * @vid_hdr_offset: VID header offset
860 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
861 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
862 * which case this function finds a vacant device number and assigns it
863 * automatically. Returns the new UBI device number in case of success and a
864 * negative error code in case of failure.
866 * Note, the invocations of this function has to be serialized by the
867 * @ubi_devices_mutex.
869 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
871 struct ubi_device *ubi;
872 int i, err, do_free = 1;
875 * Check if we already have the same MTD device attached.
877 * Note, this function assumes that UBI devices creations and deletions
878 * are serialized, so it does not take the &ubi_devices_lock.
880 for (i = 0; i < UBI_MAX_DEVICES; i++) {
881 ubi = ubi_devices[i];
882 if (ubi && mtd->index == ubi->mtd->index) {
883 dbg_err("mtd%d is already attached to ubi%d",
890 * Make sure this MTD device is not emulated on top of an UBI volume
891 * already. Well, generally this recursion works fine, but there are
892 * different problems like the UBI module takes a reference to itself
893 * by attaching (and thus, opening) the emulated MTD device. This
894 * results in inability to unload the module. And in general it makes
895 * no sense to attach emulated MTD devices, so we prohibit this.
897 if (mtd->type == MTD_UBIVOLUME) {
898 ubi_err("refuse attaching mtd%d - it is already emulated on "
899 "top of UBI", mtd->index);
903 if (ubi_num == UBI_DEV_NUM_AUTO) {
904 /* Search for an empty slot in the @ubi_devices array */
905 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
906 if (!ubi_devices[ubi_num])
908 if (ubi_num == UBI_MAX_DEVICES) {
909 dbg_err("only %d UBI devices may be created",
914 if (ubi_num >= UBI_MAX_DEVICES)
917 /* Make sure ubi_num is not busy */
918 if (ubi_devices[ubi_num]) {
919 dbg_err("ubi%d already exists", ubi_num);
924 ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
929 ubi->ubi_num = ubi_num;
930 ubi->vid_hdr_offset = vid_hdr_offset;
931 ubi->autoresize_vol_id = -1;
933 mutex_init(&ubi->buf_mutex);
934 mutex_init(&ubi->ckvol_mutex);
935 mutex_init(&ubi->device_mutex);
936 spin_lock_init(&ubi->volumes_lock);
938 ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
945 ubi->peb_buf1 = vmalloc(ubi->peb_size);
949 ubi->peb_buf2 = vmalloc(ubi->peb_size);
953 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
954 mutex_init(&ubi->dbg_buf_mutex);
955 ubi->dbg_peb_buf = vmalloc(ubi->peb_size);
956 if (!ubi->dbg_peb_buf)
960 err = attach_by_scanning(ubi);
962 dbg_err("failed to attach by scanning, error %d", err);
966 if (ubi->autoresize_vol_id != -1) {
967 err = autoresize(ubi, ubi->autoresize_vol_id);
976 ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
977 if (IS_ERR(ubi->bgt_thread)) {
978 err = PTR_ERR(ubi->bgt_thread);
979 ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
984 ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi_num);
985 ubi_msg("MTD device name: \"%s\"", mtd->name);
986 ubi_msg("MTD device size: %llu MiB", ubi->flash_size >> 20);
987 ubi_msg("number of good PEBs: %d", ubi->good_peb_count);
988 ubi_msg("number of bad PEBs: %d", ubi->bad_peb_count);
989 ubi_msg("max. allowed volumes: %d", ubi->vtbl_slots);
990 ubi_msg("wear-leveling threshold: %d", CONFIG_MTD_UBI_WL_THRESHOLD);
991 ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
992 ubi_msg("number of user volumes: %d",
993 ubi->vol_count - UBI_INT_VOL_COUNT);
994 ubi_msg("available PEBs: %d", ubi->avail_pebs);
995 ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs);
996 ubi_msg("number of PEBs reserved for bad PEB handling: %d",
998 ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
999 ubi_msg("image sequence number: %d", ubi->image_seq);
1002 * The below lock makes sure we do not race with 'ubi_thread()' which
1003 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1005 spin_lock(&ubi->wl_lock);
1006 if (!DBG_DISABLE_BGT)
1007 ubi->thread_enabled = 1;
1008 wake_up_process(ubi->bgt_thread);
1009 spin_unlock(&ubi->wl_lock);
1011 /* Flash device priority is 0 - UBI needs to shut down first */
1012 ubi->reboot_notifier.priority = 1;
1013 ubi->reboot_notifier.notifier_call = ubi_reboot_notifier;
1014 register_reboot_notifier(&ubi->reboot_notifier);
1016 ubi_devices[ubi_num] = ubi;
1017 ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1027 free_user_volumes(ubi);
1028 free_internal_volumes(ubi);
1031 vfree(ubi->peb_buf1);
1032 vfree(ubi->peb_buf2);
1033 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1034 vfree(ubi->dbg_peb_buf);
1041 * ubi_detach_mtd_dev - detach an MTD device.
1042 * @ubi_num: UBI device number to detach from
1043 * @anyway: detach MTD even if device reference count is not zero
1045 * This function destroys an UBI device number @ubi_num and detaches the
1046 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1047 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1050 * Note, the invocations of this function has to be serialized by the
1051 * @ubi_devices_mutex.
1053 int ubi_detach_mtd_dev(int ubi_num, int anyway)
1055 struct ubi_device *ubi;
1057 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1060 ubi = ubi_get_device(ubi_num);
1064 spin_lock(&ubi_devices_lock);
1065 put_device(&ubi->dev);
1066 ubi->ref_count -= 1;
1067 if (ubi->ref_count) {
1069 spin_unlock(&ubi_devices_lock);
1072 /* This may only happen if there is a bug */
1073 ubi_err("%s reference count %d, destroy anyway",
1074 ubi->ubi_name, ubi->ref_count);
1076 ubi_devices[ubi_num] = NULL;
1077 spin_unlock(&ubi_devices_lock);
1079 ubi_assert(ubi_num == ubi->ubi_num);
1080 ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1081 dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
1084 * Before freeing anything, we have to stop the background thread to
1085 * prevent it from doing anything on this device while we are freeing.
1087 unregister_reboot_notifier(&ubi->reboot_notifier);
1088 if (ubi->bgt_thread)
1089 kthread_stop(ubi->bgt_thread);
1092 * Get a reference to the device in order to prevent 'dev_release()'
1093 * from freeing @ubi object.
1095 get_device(&ubi->dev);
1099 free_internal_volumes(ubi);
1101 put_mtd_device(ubi->mtd);
1102 vfree(ubi->peb_buf1);
1103 vfree(ubi->peb_buf2);
1104 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1105 vfree(ubi->dbg_peb_buf);
1107 ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
1108 put_device(&ubi->dev);
1113 * find_mtd_device - open an MTD device by its name or number.
1114 * @mtd_dev: name or number of the device
1116 * This function tries to open and MTD device described by @mtd_dev string,
1117 * which is first treated as an ASCII number, and if it is not true, it is
1118 * treated as MTD device name. Returns MTD device description object in case of
1119 * success and a negative error code in case of failure.
1121 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1123 struct mtd_info *mtd;
1127 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1128 if (*endp != '\0' || mtd_dev == endp) {
1130 * This does not look like an ASCII integer, probably this is
1133 mtd = get_mtd_device_nm(mtd_dev);
1135 mtd = get_mtd_device(NULL, mtd_num);
1140 static int __init ubi_init(void)
1144 /* Ensure that EC and VID headers have correct size */
1145 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1146 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1148 if (mtd_devs > UBI_MAX_DEVICES) {
1149 ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES);
1153 /* Create base sysfs directory and sysfs files */
1154 ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
1155 if (IS_ERR(ubi_class)) {
1156 err = PTR_ERR(ubi_class);
1157 ubi_err("cannot create UBI class");
1161 err = class_create_file(ubi_class, &ubi_version);
1163 ubi_err("cannot create sysfs file");
1167 err = misc_register(&ubi_ctrl_cdev);
1169 ubi_err("cannot register device");
1173 ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1174 sizeof(struct ubi_wl_entry),
1176 if (!ubi_wl_entry_slab)
1179 /* Attach MTD devices */
1180 for (i = 0; i < mtd_devs; i++) {
1181 struct mtd_dev_param *p = &mtd_dev_param[i];
1182 struct mtd_info *mtd;
1186 mtd = open_mtd_device(p->name);
1192 mutex_lock(&ubi_devices_mutex);
1193 err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
1195 mutex_unlock(&ubi_devices_mutex);
1197 put_mtd_device(mtd);
1198 ubi_err("cannot attach mtd%d", mtd->index);
1206 for (k = 0; k < i; k++)
1207 if (ubi_devices[k]) {
1208 mutex_lock(&ubi_devices_mutex);
1209 ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1210 mutex_unlock(&ubi_devices_mutex);
1212 kmem_cache_destroy(ubi_wl_entry_slab);
1214 misc_deregister(&ubi_ctrl_cdev);
1216 class_remove_file(ubi_class, &ubi_version);
1218 class_destroy(ubi_class);
1220 ubi_err("UBI error: cannot initialize UBI, error %d", err);
1223 module_init(ubi_init);
1225 static void __exit ubi_exit(void)
1229 for (i = 0; i < UBI_MAX_DEVICES; i++)
1230 if (ubi_devices[i]) {
1231 mutex_lock(&ubi_devices_mutex);
1232 ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1233 mutex_unlock(&ubi_devices_mutex);
1235 kmem_cache_destroy(ubi_wl_entry_slab);
1236 misc_deregister(&ubi_ctrl_cdev);
1237 class_remove_file(ubi_class, &ubi_version);
1238 class_destroy(ubi_class);
1240 module_exit(ubi_exit);
1243 * bytes_str_to_int - convert a number of bytes string into an integer.
1244 * @str: the string to convert
1246 * This function returns positive resulting integer in case of success and a
1247 * negative error code in case of failure.
1249 static int __init bytes_str_to_int(const char *str)
1252 unsigned long result;
1254 result = simple_strtoul(str, &endp, 0);
1255 if (str == endp || result < 0) {
1256 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1268 if (endp[1] == 'i' && endp[2] == 'B')
1273 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1282 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1283 * @val: the parameter value to parse
1286 * This function returns zero in case of success and a negative error code in
1289 static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
1292 struct mtd_dev_param *p;
1293 char buf[MTD_PARAM_LEN_MAX];
1294 char *pbuf = &buf[0];
1295 char *tokens[2] = {NULL, NULL};
1300 if (mtd_devs == UBI_MAX_DEVICES) {
1301 printk(KERN_ERR "UBI error: too many parameters, max. is %d\n",
1306 len = strnlen(val, MTD_PARAM_LEN_MAX);
1307 if (len == MTD_PARAM_LEN_MAX) {
1308 printk(KERN_ERR "UBI error: parameter \"%s\" is too long, "
1309 "max. is %d\n", val, MTD_PARAM_LEN_MAX);
1314 printk(KERN_WARNING "UBI warning: empty 'mtd=' parameter - "
1321 /* Get rid of the final newline */
1322 if (buf[len - 1] == '\n')
1323 buf[len - 1] = '\0';
1325 for (i = 0; i < 2; i++)
1326 tokens[i] = strsep(&pbuf, ",");
1329 printk(KERN_ERR "UBI error: too many arguments at \"%s\"\n",
1334 p = &mtd_dev_param[mtd_devs];
1335 strcpy(&p->name[0], tokens[0]);
1338 p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
1340 if (p->vid_hdr_offs < 0)
1341 return p->vid_hdr_offs;
1347 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
1348 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
1349 "mtd=<name|num>[,<vid_hdr_offs>].\n"
1350 "Multiple \"mtd\" parameters may be specified.\n"
1351 "MTD devices may be specified by their number or name.\n"
1352 "Optional \"vid_hdr_offs\" parameter specifies UBI VID "
1353 "header position and data starting position to be used "
1355 "Example: mtd=content,1984 mtd=4 - attach MTD device"
1356 "with name \"content\" using VID header offset 1984, and "
1357 "MTD device number 4 with default VID header offset.");
1359 MODULE_VERSION(__stringify(UBI_VERSION));
1360 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1361 MODULE_AUTHOR("Artem Bityutskiy");
1362 MODULE_LICENSE("GPL");